Diagnostic and Classification Considerations Regarding Gaming Disorder: Neurocognitive and Neurobiological Features

Sex differences of neural connectivity in internet gaming disorder and its association with sleep quality: an exploratory fMRI study

Objectives

Sex-specific differences in internet gaming disorder (IGD) neurophysiology remain underexplored. Here we investigated sex-related variability in regional homogeneity (ReHo) and functional connectivity (FC) in IGD and their correlations with sleep quality.

Methods

Resting-state functional magnetic resonance imaging (fMRI) scans were performed on 52 subjects with IGD and 50 healthy controls (HCs). Two-way ANOVA was used to examine sex and diagnosis interactions in ReHo and FC, followed by post-hoc analyses to explore FC biomarkers for different sexes.

Results

In ReHo analysis, the four groups showed significant sex and diagnosis interactions in the right middle frontal gyrus (rMFG). FC analysis with rMFG as the seed region revealed a significant sex and diagnosis interaction effect in FC of the rMFG with the bilateral postcentral gyrus (PoCG). In male IGD group, FC between the rMFG and the bilateral PoCG correlates strongly with daytime dysfunction score and the Pittsburgh sleep quality inventory (PSQI) total score.

Conclusion

These findings emphasize the importance of considering sexual dimorphism in the neurobiology of IGD, which might influence subsequent treatment strategies.

Neural correlates of model-based behavior in internet gaming disorder and alcohol use disorder

Background

An imbalance between model-based and model-free decision-making systems is a common feature in addictive disorders. However, little is known about whether similar decision-making deficits appear in internet gaming disorder (IGD). This study compared neurocognitive features associated with model-based and model-free systems in IGD and alcohol use disorder (AUD).

Method

Participants diagnosed with IGD (n = 22) and AUD (n = 22), and healthy controls (n = 30) performed the two-stage task inside the functional magnetic resonance imaging (fMRI) scanner. We used computational modeling and hierarchical Bayesian analysis to provide a mechanistic account of their choice behavior. Then, we performed a model-based fMRI analysis and functional connectivity analysis to identify neural correlates of the decision-making processes in each group.

Results

The computational modeling results showed similar levels of model-based behavior in the IGD and AUD groups. However, we observed distinct neural correlates of the model-based reward prediction error (RPE) between the two groups. The IGD group exhibited insula-specific activation associated with model-based RPE, while the AUD group showed prefrontal activation, particularly in the orbitofrontal cortex and superior frontal gyrus. Furthermore, individuals with IGD demonstrated hyper-connectivity between the insula and brain regions in the salience network in the context of model-based RPE.

Discussion and Conclusions

The findings suggest potential differences in the neurobiological mechanisms underlying model-based behavior in IGD and AUD, albeit shared cognitive features observed in computational modeling analysis. As the first neuroimaging study to compare IGD and AUD in terms of the model-based system, this study provides novel insights into distinct decision-making processes in IGD.

Measurement Invariance of the Lemmens Internet Gaming Disorder Scale-9 Across Age, Gender, and Respondents

Although Internet gaming disorder (IGD) has gained increased attention in scientific, clinical, and community contexts, there is still a lack of consensus regarding the best assessment tools (i.e., self-report or other reports) for assessing its symptoms. The present study aimed to investigate the reliability, validity, and measurement invariance of both versions (youth and parent) of The Lemmens Internet Gaming Disorder Scale-9. To achieve this goal, we recruited between June and October 2019 from five Romanian highschools a total of 697 adolescents (11-19 years old) and one of their parents (N = 391). The internal consistency was good in both versions of the instrument (α = 0.772 for the youth version and α = 0.781 for the parent version). Construct validity assessed through confirmatory factor analysis showed support for the one factor structure of the scales, while multigroup confirmatory factor analysis endorsed the invariance across age, gender, and respondents (i.e., parent vs. youth report). The current research identifies both IGD scales to be reliable and valid, arguing for their utility for assessing IGD symptomatology among adolescents. Implications for theory, assessment, and future directions are discussed.

Implicit cognitions in problematic social network use

Implicit cognitions may be involved in the development and maintenance of specific Internet use disorders such as problematic social network use (PSNU). In more detail, implicit attitude, attentional biases, approach and avoidance tendencies as well as semantic memory associations are considered relevant in the context of PSNU. This viewpoint article summarizes the available literature on implicit cognitions in PSNU. We systematically reviewed articles of implicit cognitions in PSNU from PubMed, Scopus, Web of Science, and ProQuest databases based on a targeted search strategy and assessed using predefined inclusion and exclusion criteria. The present findings suggest that specific implicit cognitions are important in the context of PSNU and therefore show parallels to other addictive behaviors. However, the empirical evidence is limited to a few studies on this topic. Implicit cognitions in PSNU should be explored in more depth and in the context of other affective and cognitive mechanisms in future work.

Neuroimaging findings in adolescent gaming disorder: a systematic review

OBJECTIVES

Gaming disorder is a growing concern affecting adolescents, exacerbated by the impact of recent COVID-19 restrictions. The World Health Organization has recently included gaming disorder in the 11th International Classification of Diseases (ICD-11). However, there is still an ongoing debate about the validity and reliability of the proposed clinical criteria, despite growing neurobiological evidence in this cohort. Systematic reviews in this area have focused mainly on adults or mixed adult/adolescent populations. Therefore, this systematic review explored the neuroimaging literature in adolescents (under 18 years old) with gaming disorder.

METHODS

Using PRISMA 2020 guidelines, 3288 primary studies were identified from PubMed, CINAHL Plus, PsycINFO and Web of Science. After applying inclusion and exclusion criteria (appropriate title, abstract, comparison group used within study, English-language, neuroimaging and mean age under 18), 24 studies were included in this review.

RESULTS

Functional and structural brain alterations in adolescent gaming disorder were noted across several imaging modalities, including electroencephalogram (EEG), functional magnetic resonance imaging (fMRI) and structural magnetic resonance imaging (MRI). Compared with healthy controls, adolescents with gaming disorder demonstrated neurological changes comparable to substance addiction, namely impairments in emotional regulation, reward-seeking, inhibition and increased risky decision-making. Positive brain adaptations in the areas of visuospatial processing and memory were observed.

CONCLUSIONS

A number of key brain regions are affected in adolescent gaming disorder. These findings can help clinicians understand adolescent presentations with gaming disorder from a neurobiological perspective. Future studies should focus on forming a robust neurobiological and clinical framework for adolescent gaming disorder.

Neurobiological risk factors for problematic social media use as a specific form of Internet addiction: A narrative review

Problematic social media use (PSMU) is a behavioral addiction, a specific form of problematic Internet use associated with the uncontrolled use of social networks. It is typical mostly for modern adolescents and young adults, which are the first generations fully grown up in the era of total digitalization of society. The modern biopsychosocial model of the formation of behavioral addictions, postulating the impact of a large number of biological, psychological, and social factors on addictive behavior formation, may be quite applicable to PSMU. In this narrative review, we discussed neurobiological risk factors for Internet addiction with a focus on current evidence on the association between PSMU and structural/ functional characteristics of the brain and autonomic nervous system, neurochemical correlations, and genetic features. A review of the literature shows that the vast majority of the mentioned neurobiological studies were focused on computer games addiction and generalized Internet addiction (without taking into account the consumed content). Even though a certain number of neuroimaging studies have been conducted for PSMU, there is practically no research on neuropeptide and genetic associations for PSMU to date. This fact points to the extremely high relevance of such studies.

Functional MRI of inhibitory control processing in problematic mobile video gamers

With the development of mobile technology, mobile video games provide people with a more convenient way of entertainment, but problematic playing could also bring some negative consequences. Prior studies have indicated that Internet gaming addicts were accompanied by impaired inhibitory control. However, as a relatively new form of problematic game usage based on mobile devices, little is known about the neurobiological underpinnings of inhibitory control in problematic mobile video game (PMVG) users. Adopting an event-related fMRI Stroop task, the present study aimed to examine the different neural correlates of inhibitory control between PMVG and healthy control (HC) subjects. Compared with HC group, PMVG group showed greater brain activities in the right dorsolateral prefrontal cortex (DLPFC) during the Stroop process. Moreover, correlation analysis showed that brain activities extracted from the voxel in the DLPFC cluster had a significantly negative correlation with reward sensitivity. Our current findings may suggest the compensating effect in key brain regions of inhibitory control in problematic mobile video gamers relative to healthy controls.

Psychometric validity and the appropriateness of tolerance as a criterion for internet gaming disorder: A systematic review

Tolerance is a controversial but still an omnipresent criterion in measuring problematic gaming and Internet Gaming Disorder (IGD). Despite criticisms, a systematic review of its suitability has not been conducted until now. The aim of this study was to assess the evidence of psychometric validity and the appropriateness of tolerance as a criterion for IGD. A total of 61 articles were included in the review, 47 quantitative, 7 qualitative studies,plus 7 studies that introduce potential item wordings for operationalizing tolerance. Results showed that the tolerance item tends to have acceptable to high factor loadings on the single IGD factor. While tolerance sometimes did not adequately differentiate the engaged gamers from those with a probable disorder, it was endorsed at medium to high levels of IGD severity and had a good performance in the interviews. It, however, showed weak relations with distress and well-being. In qualitative studies, tolerance as currently defined by DSM-5 and measured by questionnaires (i.e., increasing amounts of time spent on gaming) was almost unequivocally rejected by gamers. The solid performance of tolerance in psychometric studies was probably due to deficiencies of the IGD construct, which also contains other disputed criteria. Tolerance lacks relevance in measuring IGD and care should be taken when using and interpreting IGD measures with this criterion.

Disturbed craving regulation to gaming cues in internet gaming disorder: Implications for uncontrolled gaming behaviors

BACKGROUND

The ability to control craving for games is very important to abstain from Internet gaming disorder (IGD) and abundant clinical evidence has suggested that craving dysregulation is the essential pathogenesis for IGD. However, the neural mechanism underlying this feature remains unclear.

METHODS

Subjective evaluation and fMRI data from 44 participants (IGD participants: 21; recreational Internet game users (RGUs): 23) were collected while they were performing a regulation of craving task. We analyzed and compared their brain features while they regulated cravings to gaming stimuli.

RESULTS

Compared to RGUs, IGD participants showed enhanced brain activation in the right anterior cingulate cortex, posterior cingulate cortex (PCC), orbitofrontal cortex and middle temporal gyrus and in the left dorsolateral prefrontal cortex and thalamus during the regulation of craving task. Generalized psychophysiological interaction (gPPI) analysis revealed that IGD participants showed decreased functional connectivity between the right PCC and right inferior parietal lobule compared to that in RGU participants.

CONCLUSIONS

The results suggested that deficits of craving regulation in IGD participant were associated with the imbalanced coordination between the reward network and the executive network. Enhanced game-seeking motivation and disturbed executive control are responsible for craving dysregulation in IGD participants. These findings suggest a biological mechanism for IGD that may help in finding potential interventions.

Depressive symptoms and depression in individuals with internet gaming disorder: A systematic review and meta-analysis

BACKGROUND

Although depression has frequently been associated with Internet Gaming Disorder (IGD), its epidemiological impact on this emerging condition has not been systematically assessed. In this study, we aimed to synthesize the available evidence focusing on depression and depressive symptoms in individuals with IGD.

METHODS

We searched PubMed, Embase, PsycINFO, GreyLit, OpenGrey, and ProQuest up to March 2020 for observational studies focusing on depression-related outcomes in IGD. We conducted random-effects meta-analyses on 1) rate of comorbid depression in IGD; 2) severity of depressive symptoms in IGD participants without depression.

RESULTS

We identified 92 studies from 25 different countries including 15,148 participants. 21 studies (n = 5025 participants) provided data for the first analysis, resulting in a pooled event rate of depression of 0.32 (95% Confidence Interval 0.21-0.43). The pooled Beck Depression Inventory scores in individuals without depression were suggestive of mild severity (13 studies, n = 508; 10.3, 95% Confidence Interval 8.3-12.4).

LIMITATIONS

The considerable inconsistency of methods employed across studies limits the transferability of these findings to clinical practice.

CONCLUSIONS

The prevalence of depression in individuals with IGD varied considerably across studies, affecting approximately one out of three participants overall. Furthermore, a globally major severity of depressive symptoms was found in those without a clinical diagnosis of depression, compared to the general population. These findings confirm a relevant impact of mood disturbances in IGD.

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The Clinical Consistency and Utility of ICD-11 Diagnostic Guidelines for Gaming Disorder: A Field Study Among the Chinese Population

Purpose: As a new category proposed in the International Classification of Diseases (11th Revision) (ICD-11), the reliability and clinical utility of ICD diagnostic guidelines for gaming disorder (GD) in the Chinese population have not been studied. The purpose of this field study is to clarify the reliability, clinical utility, and cultural applicability of ICD diagnostic guidelines for GD in China and its comparability with Internet GD (IGD) in the Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) (DSM-5). Methods: Participants included 21 paired clinical raters consisting of seven psychiatrists and 200 gaming players aged from 15 to 18 years with different risk levels of Internet addiction based on the scores of Young's Internet Addiction Test. Each participant received a semi-structured face-to-face interview by paired clinical raters at the same time. Then clinical raters made the diagnosis and filled the clinical utility questionnaire independently according to the diagnostic guidelines for GD in both ICD-11 and DSM-5. Results: The diagnostic consistency coefficient (kappa value) between the paired clinical raters was 0.545 (0.490-0.600, p < 0.001) and 0.622 (0.553-0.691, p < 0.001) for ICD-11 and DSM-5 diagnostic guidelines, respectively, for GD. The diagnostic consistency was 0.847 (0.814-0.880, p < 0.001) between GD in ICD-11 and IGD in DSM-5. Meanwhile, 86.7% of responses that agreed with the ICD-11 diagnostic guidelines for GD provided enough detailed implementation characteristics and showed good overall clinical applicability (86.0%), specificity (94.4%), usefulness (84.1%), and acceptable cultural adaptation (74.8%). GD in ICD-11 was slightly more accepted than IGD in DSM-5 (p < 0.001), while the clinical efficiency of ICD-11 was inferior to that of DSM-5 (p < 0.001). Conclusion: This study indicates that the ICD-11 diagnostic guidelines for GD have acceptable clinical reliability and high consistency with IGD in DSM-5. Their clinical applicability and cultural adaption are comparable with those of DSM-5. Although the guidelines still need to be adjusted for better implementation in China, this is already a great step committed to reducing the serious consequences caused by excessive gaming behaviors through effective identification and normative diagnosis, especially for adolescents.

Exercise-Based Interventions for Internet Addiction: Neurobiological and Neuropsychological Evidence

With the increase in the number of internet users, the problems associated with excessive internet use have become increasingly obvious. Internet addiction can alter neurobiology, and its symptoms can be alleviated through exercise, but whether exercise exerts these effects through neurobiological pathways is unclear. Here, we reviewed the neurobiological mechanisms of exercise-based interventions against internet addiction by searching PubMed and Google Scholar for relevant research using such keywords as “exercise”, “internet addiction”, “hypothalamic-pituitary-adrenal axis”, “neurotrophin”, and “dopamine”. This review summarizes advances in our understanding of the neurobiological processes through which exercise can reduce internet addiction, and our analysis strengthens the idea that exercise-based interventions can be effective in this regard. The available evidence suggests that exercise can increase the levels of neurotrophic factors, cortisol, and neurotransmitters; improve the morphology of specific parts of the central nervous system, such as by stimulating hippocampal neurogenesis; protect the autonomic nervous system; and control the reward urge. In other words, exercise appears to mitigate internet addiction by regulating the neurobiology of the central and autonomic nervous systems. In this way, exercise-based interventions can be recommended for reducing internet addiction.

Clarifying terminologies in research on gaming disorder and other addictive behaviors: distinctions between core symptoms and underlying psychological processes

There exists ongoing debate regarding the clinical validity of single symptoms of and diagnostic criteria for gaming disorder. In particular, the potential symptom of gaming disorder that addresses coping with and escaping from negative feelings has received much attention and remains a focus of intensive discussion. We argue that it is important to consider differences or distinguish between, on the one hand, symptoms of and criteria for a disorder due to addictive behaviors, such as gaming disorder, versus, on the other hand, motivations, mechanisms, and psychological processes that may be involved in promoting addictive behaviors and that may explain symptom severity and course of the addictive disorder including potential treatment responses.

Common neurobiological and psychological underpinnings of gambling and substance-use disorders

Both psychological and neurobiological studies in gambling disorder have increased in the past 10-15 years. This review examines the current state of the literature, with a focus on recent magnetic resonance imaging (MRI) studies in gambling disorder. The review compares and contrasts findings across gambling and substance-use disorders. Additionally, features with arguably particular relevance to gambling disorder (e.g., "near-miss" processing) are described, as well as their relationship to choice behaviors. More broadly, the review informs on how these studies advance our understanding of brain-behavior relationships relating to decision-making and key features of addictive disorders.

A preliminary study of disrupted functional network in individuals with Internet gaming disorder: Evidence from the comparison with recreational game users

Although online gaming may lead to Internet gaming disorder (IGD), most players are recreational game users (RGU) who do not develop IGD. So far, the topological organization of whole-brain functional networks in IGD remains poorly understood. The inclusion of RGU as a control group could minimize the potential effects of gaming experience and gaming-related cue familiarity on the neural characteristics of IGD subjects. In the present study, we applied graph theoretical analysis to preliminarily explore the topological organization of intrinsic functional brain networks in IGD. 61 IGD participants and 61 matched RGU participants were recruited to undergo a resting-state functional magnetic resonance imaging scan. The whole-brain functional networks were constructed by thresholding partial correlation matrices of 90 brain regions, and graph-based approaches were applied to analysis their topological attributes, including small-world, efficiency, and nodal centralities. Both of IGD and RGU groups showed efficient and economic small-world topology in brain functional networks. Although there was no significant group difference in global properties, subjects with IGD as compared to those with RGU showed increased nodal centralities in the reward, craving, emotional memory and sensory-motor processing regions. These results suggest that the functional network dysfunction, characterizing by heightened incentive motivation and sensory-motor coordination, may provide a new perspective for understanding the neural characteristics underlying IGD.

Comparison of Behavioral Changes and Brain Activity between Adolescents with Internet Gaming Disorder and Student Pro-Gamers

While pro-gamers play according to defined living habits and planned schedules, adolescents with internet gaming disorder (IGD) exhibit irregular lifestyles and unregulated impulsive gaming behavior. Fourteen IGD adolescents and 12 pro-gaming students participated in this study. At baseline and after one year, demographic data, the Child Behavior Check List (CBCL), depressed mood, anxiety, and resting-state functional magnetic resonance imaging were assessed. Over the year, IGD adolescents played games as per their usual schedule, while pro-gamer students played according to their school’s team schedule. After one year, the pro-gamers’ scores had decreased in the CBCL-total (total problematic behaviors), CBCL-externalizing (under-controlled behavior, like impulsivity and aggression), and CBCL-internalizing (over-controlled behavior like depression and anxiety) compared to those of the IGD adolescents. Both groups displayed increased brain activity in the parietal lobe (a component of the attention network) over the years. Compared to pro-gamers, IGD adolescents showed higher brain activity within the left orbitofrontal cortex. Brain activity within the orbitofrontal cortex was associated with CBCL-externalizing scores. These results suggest that gaming had increased the attention network’s brain activity, but a well-organized support system could lead to different results, in terms of improved behaviors and suppressing brain activity within the orbitofrontal cortex.

Unique versus shared associations between self-reported behavioral addictions and substance use disorders and mental health problems: A commonality analysis in a large sample of young Swiss men

BACKGROUND AND AIMS

Behavioral addictions (BAs) and substance use disorders (SUDs) tend to co-occur; both are associated with mental health problems (MHPs). This study aimed to estimate the proportion of variance in the severity of MHPs explained by BAs and SUDs, individually and shared between addictions.

METHODS

A sample of 5,516 young Swiss men (mean = 25.47 years old; SD = 1.26) completed a self-reporting questionnaire assessing alcohol, cannabis, and tobacco use disorders, illicit drug use other than cannabis, six BAs (Internet, gaming, smartphone, Internet sex, gambling, and work) and four MHPs (major depression, attention-deficit hyperactivity disorder, social anxiety disorder, and borderline personality disorder). Commonality analysis was used to decompose the variance in the severity of MHPs explained (R²) by BAs and SUDs into independent commonality coefficients. These were calculated for unique BA and SUD contributions and for all types of shared contributions.

RESULTS

BAs and SUDs explained between a fifth and a quarter of the variance in severity of MHPs, but individual addictions explained only about half of this explained variance uniquely; the other half was shared between addictions. A greater proportion of variance was explained uniquely or shared within BAs compared to SUDs, especially for social anxiety disorder.

CONCLUSIONS

The interactions of a broad range of addictions should be considered when investigating their associations with MHPs. BAs explain a larger part of the variance in MHPs than do SUDs and therefore play an important role in their interaction with MHPs.